1021155620551 has 4 divisors (see below), whose sum is σ = 1113987949704. Its totient is φ = 928323291400.

The previous prime is 1021155620549. The next prime is 1021155620567. The reversal of 1021155620551 is 1550265511201.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1021155620551 - 2¹ = 1021155620549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021155620531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46416164560 + ... + 46416164581.

It is an arithmetic number, because the mean of its divisors is an integer number (278496987426).

Almost surely, 2^{1021155620551} is an apocalyptic number.

1021155620551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1021155620551 is a deficient number, since it is larger than the sum of its proper divisors (92832329153).

1021155620551 is an equidigital number, since it uses as much as digits as its factorization.

1021155620551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92832329152.

The product of its (nonzero) digits is 15000, while the sum is 34.

The spelling of 1021155620551 in words is "one trillion, twenty-one billion, one hundred fifty-five million, six hundred twenty thousand, five hundred fifty-one".